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Our key tasks

We are primarily tasked with providing power transmission services, system services and facilitating the energy market. Our core tasks follow from our appointment as grid operator under the Dutch 'Elektriciteitswet' (E-wet) and the German 'Energiewirtschaftsgesetz' (EnWG).

Our grid

TenneT manages the high-voltage grid in the Netherlands and large parts of Germany. TenneT transmits electricity at 110,000 volts (110 kV) and higher. With over 22,000 kilometres of high-voltage lines, we cross borders and connect countries.

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Electricity market

The energy sector is developing rapidly. The process of European market integration began some years ago. Its purpose is to create a single European market that enables market parties to trade gas and electricity across national borders easily and efficiently.

Company

TenneT is a leading European electricity transmission system operator (TSO), with activities in the Netherlands and in Germany. We strive to ensure a reliable and uninterrupted supply of electricity in our high-voltage grid for some 41 million people.

Procurement

SylWin1

160 kilometer long subsea cable for the connection of wind farms off the coast of Sylt

Facts

Connection

205 km long and 864 MW capacity

45 km onshore cable

160 km offshore cable

Grid connection point

converterstation Büttel Germany

Status of project

online since april 2015

About the project

SylWin1

SylWin1 is a 864 megawatt (MW) grid connection in DC technology. In order to connect the wind farms DanTysk, Sandbank and Butendiek in the Eastern North Sea region, it is necessary to bridge a distance of about 205 kilometres to the transmission system.

The wind farms are located up to 70 kilometres west of Sylt. Via SylWin1 they can feed in large quantities of wind power into the German power grid. On the offshore converter platform SylWin alpha the three-phase alternating current generated by the connected offshore wind farms is converted into DC power. The grid connection comprises about 160 kilometres of subsea cable and 45 kilometers of land cable. The subsea cable route in the coastal waters as well as the land cable are running parallel to the line for the projects HelWin1 and HelWin2.

In the onshore converter station in Büttel the DC power is re-converted into AC power and fed into the transmission system through the local substation. The jacket, the subconstruction of the offshore converter station, was put up in April 2014. In summer 2014, the further erection of the converter platform SylWin alpha took place with the placing of the topside. The converter station as well as the laying of the DC cables is completed. The laying of the AC cables to the offshore wind farms Dan Tysk, Butendiek and Sandbank and the appropriate cable entry works have been completed.